News reports say Japanese police have arrested a man for allegedly making bomb threats against the U.S. Embassy in Tokyo, and say he is also a possible suspect in death threats against Ambassador Caroline Kennedy.

Public broadcaster NHK said Thursday that Tokyo police arrested Mitsuyoshi Kamiya, a resident of the southern island of Okinawa, for allegedly making the bomb threats from a pay phone in downtown Okinawa. It said he also is believed to have threatened to bomb Camp Schwab, a U.S. military base on Okinawa. The island is home to about half of the 50,000 American troops in Japan.

NHK said police also suspect Kamiya made phone calls threatening to kill Kennedy and the U.S. consul general on Okinawa.